1. Field of the Invention
The present invention relates to resin compositions having good compatibility and superior transparency.
2. Description of the Prior Art
Ethylene-vinyl alcohol copolymer (hereinafter referred to as EVOH) is, as it is, insufficient in softness, mechanical properties, particularly in impact strength. To improve these disadvantages, thermoplastic polymers other than EVOH, such as polyolefins are often blended with EVOH. On the other hand, thermoplastic resins such as polyolefins are insufficient in gas barrier properties, and to improve this, EVOH is often blended with such resins. Japanese Patent Publication No. 20615/1974 discloses a process for improving the mechanical properties, particularly impact strengths, of EVOH, which comprises treating EVOH with a boron compound such as boric acid, borax, trifluoroboron, an alkyl borane or an aryl borane.
However, blends of EVOH and another thermoplastic polymer such as polyolefin, having poor affinity and compatibility with each other, give molded products or films having markedly low mechanical properties and transparency. For the purpose of overcoming these problems, a variety of processes have been proposed, with no substantial success; and development of a novel process to solve these problems has been desired.
Further, as apparent from Comparative Example 2 to be described later herein, blends of EVOH treated with a boron compound, such as boric acid, and thermoplastic polymers, such as polyolefins, have insufficient compatibility and give molded products having insufficient transparency.